CA1266549A - Hydrophilic polyurethane/polyurea sponge - Google Patents

Abstract

HYDROPHILIC POLYURETHANE/POLYUREA SPONGE

Abstract A water-absorbing sponge comprises at least one of a pendent sulfo-group containing polyurea and polyurethane, the polymer containing at least one sulfonate equivalent per 20,000 molecular weight units.

Description

~66~;~9 HYDROPHILIC POLYURETHANE/POLYUREA SPONGE
Technical Field This invention relates to a hydrophilic polyurethane/
polyurea sponge and a process therefor. The synthetic sponge is useful in home and industrial cleaning applications.
Background Art Cellulose sponges are in wide use for many cleaning applications. The process for providing cellulose sponges is environmentally disadvantageous due to toxic gaseous and liquid by-products.
Polyurethane sponge materials have been known and utilized for a long time. Most of these sponges are synthesized from isocyanate terminated polyethyleneoxide, polypropyleneoxide, polyesters, or combinations thereof. Coreactants are usually polyols or polyamines of similar polymeric backbones. Water is also used as a coreactant which generates a blowing agent (i.e.
carbon dioxide) in addition to generating a crosslinked system.
The majority of these materials produce a sponge material with little hydrophilic character ~moderate bulk hydrophilicity, but poor surface properties), and few of the characteristics associated with a cellulose sponge. Materials which are claimed to be hydrophilic usually contain a sacfificial hydrophilic compound or have excessive swell (in excess of 50%).
Isocyanate terminated sulfopolyethyleneoxide prepolymers have been described in U.S. Patent 4,558,149 and also in U.S.
Patent 4,746,717. Other sulfonated prepolymers for foam applications are described in U.S. Patent No. 3,988,268. The use 1~Ç;6549

- 2 - 50557-3124 of sulfonated urethanes have otherwise been mainly restricted to the synthesis of water-soluble or water-dispersible materials, e.g. U.K. Patent ~o. 1,483,687. Prepolymers based on isocyanate-terminated polyethyleneoxide are described in U.S. Patent Nos.
4,160,076; 4,384,050; 4,384,051; and 4,377,645.
Summary of the Invention Briefly, the present invention provides a water-absorbing sponge comprising at least one of sulfo group-containing polyureas and polyurethanes, the polymers containing at least one sulfonate equivalent per 20,000 molecular weight units.
Preferably, the polymers contain one sulfonate equivalent per

3,000 to 10,000 molecular weight units.
In another aspect, this invention provides a hydrophilic polyurethane/polyurea sponge which is the reaction product of a symmetric or unsymmetric isocyanate-terminated sulfopolyurethane/
urea comprising in its backbone linear or hranched organic groups which may be 1) aromatic cycloaliphatic or aliphatic ether groups, 2) aromatic, cycloaliphatic or aliphatic ester groups, 3) a central arenepolyyl or alkanepolyyl group containing a pendant sulfonate group, and is end-capped with isocyanate groups, and coreactants which include either 1) water and/or 2) a polyol or a polyamine plus a blowing agent.
In many applications it is desirable for a sponge to resist excessive shrinkage upon drying. In particular, sponges which are laminated to abrasive scrubbing pads, which are commonly used for household and industrial cleaning, become unattractive and in some instances undergo adhesive failure of the laminate ;L;;~Ç~6S4~
- 2a - 60557-3142 upon drying. Large variations in volume between the swollen and dry state of a sponge can be detrimental in such applications.
The sponges of the instant invention, surprisingly, are superior to cellulose-based sponges in that upon drying they exhibit considerably less shrinkage, 3 ~6~49 i.e., 30%, 90%, or even up to S0'~ less shrinkage compared to cellulose-based sponges. rhe total water absorption and rate of water take-up is at least as good or better than cellulose-based sporlges. FurtlleL, tl~e wet wipe capability of the sponges of the instarlt inverltion is ellual to that of cellulose-based sponges and is superior to that of natural sponges and known polyuretllarle sponges.
'l'he preferred article of the invention llas open cells which range in size from 3.0 cm to less than 1.0 micrometer, preferably 1.0 cm to less than 1.0 micrometer, has a dry density in tlle range of 0.03 to 0.1 g/cm3 and preferably has a volun~etric swell in water of less than 30%. The sponye is eyual to or improves upon existing cellulose derived sponges in tl~e following areas of performance: wet wipe, rate o~ water absorption, percent swell in water (reduced shrinkage upon drying), tensile strength, and toughness.
n this application "sporlge" means a porous, open-cellular mass capable of absorbing liquids, and is elastic and flexible when damp;
"flexible" means can be bent througl~ an angle of 180 without cracking or breaking;
"wet wipe" means the ability of a damp sponge to remove water from a surface;
"aliphatic" means linear, branched, or cyclic unless otherwise stated;
"isocyanate-terlllillated sulfopolyurethalle" means a compound having in its backbone two organic groups selected from linear, branched, and cyclo-alipllatic groups, and aromatic groups which can be interrupted by nonperoxidic oxygen atoms or ester groups, a central arenepolyyl or alkanepolyyl group containing at least one pendant sulfonate salt group between tlle organic gLoups, and is end-capped with isocyanate yroups; exact symmetry is not required but the central arenepolyyl or alkanepolyyl group is always locate~ between the two organic groups;
"lower alkyl" means 1 to 4 carbon atoms;

~66~9

4 60557-3142 "pendant" means suspended from the main chain (backbone) of the polymer;
"catenary" means in the main chain or backbone and not in a pendant or terminal group;
"sulfo" means a -S03H group or a salt thereof;
"sulfocompound" means a compound containing a pendant sulfo group; and "plurality" means a number of three or more.

Detailed ~escriPtiOn In a preferred embodiment the sponge comprises a plurality of units having the formula O~ O O O
T -Rl x~ R2 llX Rl ~c j R
H ( 3 )d H b wherein R is an organic group having a valence of 2, 3 or 4, selected from linear and branched aliphatic groups having 2 to 12 carbon atoms, 5- and 6-membered aliphatic and aromatic carbocyclic qroups having 5 to 50 carbon atoms, each Rl is independently a linear or branched aliphatic group havlng a valence of (b + 1) consisting of a chain of up to 110 carbon atoms in units selected from linear groups CnH2n and CnH2n 2 in whlch n is 2 to 12, 5- or 6-membered carbocyclic groups, and aromatic groups of 5 to 4a 60557-3142 20 carbon a~oms, which are separated by O O
individual oxygen atoms, -OC-, and -NH~- groups, the aliphatic group having a molecular weight of up to 2000, wherein b is an integer of l, 2 or 3; and R2 has a valence of d+2 and is an arenepolyyl group ~polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atom~, wherein d is a nu~ber 1, 2 or 3, X is independently -O- or -NH-, and M ls a cation.
In a further preferred embodiment the isocyanate-terminated sulfopolyurethane/urea comprises a co~pound having the formula O O O O
(CN)aR7~X R1xcR2_cx_Rl.x_lNR(NCO)a H ~SO3M)d H b and, optionally, at least one of compounds having the formulae OCNR(NCO)a and R [XCIR(NCO)a]b+

wherein R is an organlc group having a valence of (a ll) selected from linear and branched groups having 2 to 12 carbon atoms, 5- and 6-membered carbocyclic groups having 5 to 50 carbon atoms; a is a number having a value of 1, 2 or 3;

~`Yd

5~

4b 60557-3142 R1 is independently selected from a linear or branched organic group having a valence of (b + 1) comprising a saturated or unsaturated chain of up to 110 carbon atoms selected from linear groups CnH2n and CnH2n_2 in which n is 2 to 12, aromatic groups of 5 to 20 carbon atoms, and 5- or 6-membered carbocyclic ~roups, which optionally are separated by individual oxygen atoms, O O
Il 11 -OC-, and -NHC- groups, the orqanlc group having a molecular weight of up to 2000, wherein b is an integer of 1, 2 or 3;
R2 has a valence of d+2 and is an arenepolyyl group (polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atoms, and d is a number having a value 1, 2 or 3;
X is independently -0- or -NH-; and M is a cation.
The present invention further provides a sponge comprising a plurality of units having the formula O O O -o R~ -R1-Xc-R2-cx-R - XCN-R
H b (S3M)d _ l b 0 and a plurality of units selected from urea units, -NHCNH-O O
and R3- NHCNH ~c' biuret units, -NHCN-, and urethane units, 3 0 l O~CNH-R OCNHJC wherein

6~

4c 60557-3142 R is an organic group having a valence of 2, 3 or 4 and can be selected from linear and branched aliphatic groups having 2 to 12 carbon atoms, 5- and 6-membered aliphatic and aromatic carbocyclic groups having 5 to 50 carbon atoms;
Rl is an independen'ly selected linear or branched organic group having a valence of (b+l) that is the residue of an aliphatic or aromatic polyether, polyester, or polyamide polyol or polyamine having the formula HXR ( XH ) b in which Rl is a chain of up to about 110 carbon atoms of units selected from linear groups CnH2n and CnH2n 2 in which n is an integer of 2 to 12, 5- or 6~membered ~.~

1%66~9 carbocyclic yroups, and aromatic groups of 5 to 20 carbon atoms, whicll aLe separated by individual oxygen atoms, -O~-, and --NIIC-grolJps, the organir: gloup having a molecular weiyht oE up to ahout 2000, wheLein b is an integer of 1, 2, 3;
R is an arenepolyyl group ~)olyvalent arene group) having a valence of d+2 having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group haviny 2 to 20 carbon atoms remaining after the removal of two carboxyl gLoupS and d sulfo groups from sulfoarene and sulfoalkane dicarL>oxylic acids having the formula I~OC-R2-COII VIII
3M)~
~0 in wllicll M is a catiorl, and preferably M is at least one of Na, hut M can be ~1, an alkali metal ion such as K or Li, an alkaline earth metal cation (e.g., Mg, Ca, or sa), or a primary, secon~ay, tertiary,.or quaternary ammonium cation such as ammonium, methylammorlium, butylammonium, diethylammonium, triethylammoniulll, tetraethylammonium, and benzyltrimethylalllmc)rlium cation, and d is a number having a value of 1, 2, or 3;
R3 is a linear or branched aliphatic group having - 2 to 50 carbon atoms or an aromatic gruop of 5to 50 carbon atoms and a valence of c in wllich c is a number having a value of 2 to 5, the yrouU optioncllly containiny 1 to 20 nonperoxidic oxygen atom, ~.~6G$4~9 O O
Il 11 -CO- and -CNH- groups, or R3 is a 5- or 6-, membered cycloalphatic group or aromatic group having 5 to 20 carbon atoms; and X is independently -O- or -NH-.
The sponge of the invention which comprises a polymeric 3-dimensional network and has an absorptive capacity of 10 to 50, preferably 10 to 30 grams of water per gram of dry sponge, and a rate of water absorption of 0.001 to 0.04 g/cm2/5 seconds, a density in the range of 0.01 to 0.4 g/cm3, preferably 0.03 to 0.1 g/cm3, and a percentage volumetric swell in water of less than 50~, preferably less than 30%, and most preferably 15 to 25~, and wet wipe capacity of 85 to about 100~, and as noted above, has additional properties equal or better than those of cellulose and natural sponges. The sponge of the invention can be prepared by a process that is simpler than the process for preparing cellulose sponges, and does not produce large quantities of environmentally damaging by-products.
In the process of the invention the polyurethane/
polyurea sponge is provided by the reaction of 1. About 1 equivalent of a mixture comprising an isocyanate-terminated sulfopolyurethane/urea (Formula V), and optionally, and preferably, one or both of an isocyanate-terminated polyurethane/urea (Formula Va), and a polyisocyanate (Formula IV), which are described in detail in assignee's U.S. Patent 4,746,717, which is a CIP of U.S. Patent No. 4,558,149, issued December 10, 1985, and which have the formulae N~aR-Ncx3Rl-xc-R2-co-Rl{xcN-R~Nco~ a V

H (S03M)d ~ b ., R [XC7R(NCO)a]b+1 and Va H

OCNR(NCO)a IV
wherein R, R1, R2, X, M, b and d are as defined above, and a is a number having a value 1, 2 or 3, and which isocyanate-terminated polyurethane/urea preferably has a molecular weight in the range of 300 to 5,000 with 2. a coreactant which can include at least one of a) 1 to 50 moles of water, and b) about 0.8 to 1.2 moles of a polyol and~or 0.05 to 1.5 moles of a polyamine plus a blowing agent.
Preparation of an isocyanate-terminated sulfopolyurethane can involve an excess of polyisocyanate of Formula IV in the reaction with a sulfopolyol or sulfopolyamine in an amount up to about 100% excess (e.g., up to about four moles of polyisocyanate per mole of sulfopolyol or sulfopolyamine). When such an excess is used the isocyanate-terminated sulfocompounds of Formulae V and Va mixed with excess polyisocyanate is obtained.
The process of the invention is depicted in the FLOW

CHART below wherein R, R1, R2, R3, ~, M, a, b, c, and d are as defined above.

a) 1~66549 a~ ., .$ v o 7~ P a o ~ z O bO ~ P~ a~
O ~ Z V) 'Z~ Z ~ ~ H
~I H O U ~ D

) t'~

O ~ ~ ~ _ ~
O Z V p o ~J ~--Z
o=~ e \ ~. o=~ ~ ~ o ~ ~
O ~ ~ bO

O _ ~ ) _ Ql O + 3 ~ a _ o ~,~ e \
~ ~ =~ ~ ~

~ ~ 05Z~
Vl \

D~ ~ O ~q C~ O
+ ~J ~~'Z' Oa V (~ C ~:;
C~ e ~ 0=~_~

o=~) ~ o o=Z ~ ~ 11 c~ o_O H ~ a ,~--z o V ~ v o=~ H a m O ~ ~--z ~H ~1 Ul 3 , ~2~6~S49 Steps (a), (b)(l), and (b)(2) wl~ich provide the isocyanate-termillated snlfopolyllretllane/uLea of Folmlllae V
and Va have beell desc~ e(3 in lJ.S patent 4,746,717.
Preferably, it is preL)aL-e(l by tllc leaction of olle m(Jle of sulfoarene or sulfoalkane dicarl)oxy]ic acid, Formula T, (or tlleir esters prepared from an alcol~ol of low molec~llal weight, i.e. below ahollt 9q, their acid anhydrides, or their acid halicles) with two to Eour moles of morlomeric or polymeric polyol or polyamine of Formula II having (~
10 910UpS selected from amil-lo an(l l-ydroxyl groups formill(J a sulfor)olyol or sulfoL~olyamine designated a sulfocomE)oull(l havillg 2b hydroxyl and/or amil-o groul)s, whereil- b is an integer of l, 2, or 3. Wllerl m~re than two moles of monomeric or polymeric polyol Ol polyamine is used isocyanate-terlninate(l polyuretllalle/u~ea of Formula V is also formed. ~ e sulfocomL~un~ (Formula III ) or ttle mlxture of sultocompound and com~)oun(l of Formllla Va is then caused to react with from 2b to ul) to l6b plus B moles of an organic polyisocyarlate to form an isocyanate-telmillated sulfocompound. As i6 knowll ill tlle aL~, these rea~tiol-s can be performed in the presence of a mercury, leacl or tin catalyst such as dibutyltin dilaurate. Pleferably, tlle catalyst is a tertiary amine, tricalcium aluminate, or the uotassium salt of a molybdenum ester of triethyleneglycol as is disclosed in U.S. Patent No. 2,916,464. 'I`he preparation of tlle sulfocompoun~ can l)e carried out by l)eating tlle reactants for about 2 to 20 hours, preferably 4 to 10 hours, at temueratures from 150 to 300C, preferably 200 to 250C, uncler reduced pressure or an inert atmosphere.
Polyols (IIO)bRlOll of E'ormula II, whicll can be aliphatic or aromatic polyols, useful in preuaring the polyurethane/polyurea sponges of tlle invention have a molecular weight of 62 UL) to 2000 and include, for example, monomeric and polymeric polyols havillg two to four llydroxyl groups. Examples of the monollleric polyols include ethylene ~lycol, propylene glycol, butylene glycol, hexamethylene 1~Ç;6549 -` -10-glycol, cyclohexamethylenediol, 1,1,1-trimethylolpropane, pentaerythLitol, and tlle like. Examples of polymeric polyols include the polyoxyalkylene polyols ~i.e., the diols, triols, and tetrols), the polyester diols, triols, and tetrols of or~anic dicarboxylic acids and polyhydric alcohols, and the polylactone diols, triols, and tetrols having a molecular weigllt of 106 to about 2000. Examples of polymeric polyols include polyoxyethylene diols, triols and tetrols such as the Carbowax1M polyols available from ~nion Carbide, Danbury, CT, the polyoxytetramethylenediols such as Polymeg M polyols available from Quaker Oats Company, Chicago, IL, the polyester polyo]s such as tlle MultronTM poly(ethyleneadipate)polyols available from Mobay Chemical Company, and the polycaprolactone polyols such as the PCPTM polyols available from Union carbide.
Examples of aromatic polyols include the polyester polyols that are prepared from aromatic dicarboxylic acids such as o-, m-, and p-phthalic acid and excess diols such as diethylene glycol, triethylene glycol, glycol, glycerine, and pentaerytllritol; and from dicarboxylic acids S-lCh as adipic acid and resorcinol.
Examples of monomeric polyols include resorcinol and o-, m-, and p-xylene-~,'-diol.
Polyamines of Formula II have a molecular weight of 60 to 2000 and include monomeric and polymeric primary and secondary aliphatic and aromatic amines having two to four amino groups. Examples include alkylene diamines such as ethylenediamine, triethylenetetraamine, diethylene-triamine, piperazine, as well as other polyamines such as the polyamines available from Jefferson Chemical Co., Inc., a subsidiary of Texaco, Inc., under the trade name JeffamineTM such as JeffamineTM D-400, a polyoxypropylene - diamine having a molecular weight of about 400; JeffamineTM
D-230, a polyoxypropylene diamine having a molecular weight of about 230; Jeffamine q'-403, a polyoxypropylene triamine having a molecular weight of about 400; and JeffamineT ED 600 and ED 900, which are polyoxyethylene i6S49 diamines having molecular weights of 600 to 900, respectively. In addition, hydrazino comounds such as adipic dihydrazide or ethylene dihy(3razine can be used, as can also, alkanolamines such as ethanolamine, diethanolamine, and tLis(hydroxyethy)ethylenediamine. The po'ymeric polyols an(l polyamines that have a molecular weight of about 300 to 1000 are prefe~red.
Sulfoarene- and sulfoalkanedicarboxylic acids of Formula I useful for preparation of the polyurethane/
polyurea sponges of the invention are any of the known sulfoarene- and sulfoalkanedicarboxylic acids. Examples of these include sulfoalkanedicarboxylic acids such as sulfosuccinic acid, 2-sulfoglutaric acid, 2,5-disulfoadipic acid, 2-sulfo(lodecanedioic aci(3, sulfoarerledicarboxylic acids such as 5-sulfonaphthalerle-1,4-~icarboxylic acid, 4,5-disulfonaphthalene-1,8-dicarboxylic acid, sulfobenzylmalonic acids such as those described in U.S.
Patent No. 3,821,2~1; and sulfofluorenedicarboxylic acids such as 9,g-di(2'-carboxyethyl)fluorene-2-sulfonic acid described in ~ritish Patent No. 1,006,579. It is understood that the corresponding lower alkyl esters, halides, anhydrides, and salts of the above sulfonic acids can also be used in the preparation.
Polyisocyanates, Formula IVI that can be used to react with the sulfocompounds, Formula III, to form the isocyanate-terminated sulfocompounds that are intermediates to the polyurethane/polyurea sponges of the invention are any of the well-known polyisocyanates. Preferred polyisocyanates are hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, 3,5,5-tri-methyl-1-isocyanato-3-isocyanatomethylcyclohexane, 4,4'-diphenylmethane diisocyanate (MDI), 4,4'4"-triisocyanatotriphenylmetllane, and the polymethylenepolyphenylisocyanates. Other polyisocyanates are well known and include those described in U.S. Patent Nos. 3,700,643 and 3,600,359 among many others. Mixtures of polyisocyanates can also be used such as the mixture of MUI and trimer of MDI available from Upjohn Polymer Chemicals as Isonate 143L "Liquid MDI".
It is also within the scope of the present invention to add up to 2 weight percent water with the polyisocyanate in step (b). ~l'he addition of water creates urea linkages in compounds V and Va.
~ rhe polyurethane/polyurea sponges of the invention can be provided by any of steps Ic), (d), and (e). In step (c), about 1 e~uivalent of isocyanate-terminated sulfocompound mixture comprising compounds ofFormulae V, Va, and IV, is admixed with 1 to 50 moles of water. Preferahly, 0.01 to 5.0 weight percent of a surfactant such as a llOI~iOlliC alkylphenyl polyether alcohol (PIuronic L--6~M, ~ASF wyall~3Otte corp, Parsippany, NJ) and 0.0 to 2.0 ~eight percent of a catalyst such as N-ethylmorpholine ~Texaco Cllemical Co.) is added. Other useful catalysts include tin catalysts or urethane catalysts such as those available as DAscoTM (Air Products and Chemicals, lnc., ~llentown, P~ lthough a catalyst can be used in step ~e), one generally is not needed. The catalyst preferably is ad(led witll the water, beFore admixing with the isocyanate-terminated sulfopolyurethane, to accelerate crosslinking of the resin and CO2 evolution and to provide lower density and a more open structured sponge. Useful blowing agents include any gas or volatile organic compound that dissolves in the compound of Formula V, such as trichlorofluoromethane (Freon-113~M, Dupont de Nemours Co., Wilmington, DE). rhe reaction mixture is subjected to high speed mechanical stirring, preferably for 30 20 to 30 seconds at about ~00 rpm at ambient conditions, and then it is immediately poured into a flat vessel, whereupon an expansion of the resin takes place. In this expansion of the resin, carbon dioxide gas is released in a chemical reaction which causes a porous, open-cellular mass to form. 'l'he resulting sponge is trimmed to remove the outer skin and thell is oven-cured at low temperatures (35 to 80C, preferably about 50~C) for 0.5 to 6 hours, preferably about 2 hours.

.......

I~ the sponge is prepared via step (c) lt can bc one or more than one 3-dimensional crosslinked molecule having a plurality of units ~1 o 11 ~1 O

P-N-C-N-P + P-N-C-N-P
0=1 urea N-P
VIII
biuret IX
wherein1l l R 2R
P = ~RNCX)bR XC~ CXR (XC1R~b 11 (SO3 )d and R, Rl, R2, M, X, b and d are as defined above.
If the sponge is prepared via steps (d) or (e), the procedure is modified as follows:
lo about l mole o~ the isocyanate-terminated sulfopolyurethane/urea mixture of compounds of Formula V, Va, and IV, 0.~ to 1.2 moles of a polyol R (O11)C (Formula VI) or 0.5 to 1.5 moles of a ~olyamine R (N112)C (Formula VII) is added l to 20 weight percent (preferably 5 to 15 weight percent) of a blowing agent. The blowing agent is admixed using the procedure as for step (c). The reaction of step (d) preferably includes a catalyst and amount as described in step (b). Step ~P) generally requires no catalyst. In steps (d) or (e) it may be advantageous to use an amount of water in addition to or instead of the blowing agent, i.e., O.Ol to 40.0 weight percent, to be added to the polyol or polyamine to augment or supply the necessary blowing agent.
Polyols, R3(O~1)C, and polyamines, R3(N~12)C that can be used in steps (d) and (e) preferably are the aliphatic polyols and polyamines of Formula II. Aromatic polyamines suc11 as 1,2-, 1,3-, and l,4-phenylenediamine, toluenediamine and the like can be used in amounts ~2~6549 . , ~ ...

(generally up to about 50~ by weigllt). ~rl.e sulfopolyols of Formula III can also be used in step (d).
In steps (c), (d), and (e) the product may compLise a mixture of polyurea (VIII) and/or (XI), polyurethane (X), and biuret units (IX).
~ blowing agellt is useful wi~h tlle polyamine or polyol of reaction steps (d) OL (e) in preparing the sponge of the invention. Useful blowing agents include C1 to C~
hydrocarbons, C1 and C2 clllorinated llydrocarbons SUCIl as methylene chloride, dichloroet1lene, monofluorotrichloro-methane (Freon 113lM, ~upont), difluorodichlorometllane, acetone, as well as nonreactive gases such as carbon dioxide, nitrogen, or air.
~s is knowll in the art, there can be incorporated in the sponges during their preparation various a~juvants such as fillers and fibers (e.~., nylorl, rayon, cellulose, polypropylene, diatomaceous clays and ot~ler inorganic fillers), deodoLants, medicinals, insecticides, fungicides, antimicrobials, humectants, pigments, or dyes.
The polyuretharle/polyure3 sponges of the present invention exhibit water absorption rates equal to or better than cellulose sponges of comparable density, equivalent absorption capacity to cellulose sponges, and hav dramatically reduced swell, i.e., swell in volume of less than 30% while cellulose spollges swell up to 60% or mole.
'l'he sponges of the present inventioll find use in home and industrial applications including in nonwoven sponge laminates (e.g., comprising Scotcl~brite sponge laminates, 3M, St. Paul, MN), sponge laminates to fabrics, syr-tlletic chamois, personal care, and medical products.
In the Examples below the following test methods were used:

l. Procedure for Measurement of Percent Swell A sponge sample appLoxilllately 5cm x 5cm x 0.6cm was oven dried at 6~DC for 6 hours. 'l'lle lengt1l, width, and thickness of the sponge were measured in order to calculate -15-- ~2~49 the dry volume. ~rlle sponge was therl thoroughly saLurated with water (approximately 1 hour soaking in water to permit total possible swell), wruny out, and the dimensions measured in order to calculate wet volume. The percent volume change (percent swell~ was calculated by ,Vwe,t,,,-,,V,~ry x 100 = percent swell V(~ry 2. Procedure__or Measuremen_ of Ra_e_of Absorption A sponge sample of approximately 5cm x 5cm x 0.6cm was prepared by soaking in water for 1 hour prior to testing. The sponge was wrung out, weighed, and the length and width of this sponge were then measured. Rate of water absorption was measure~ in a wateL colltainer equipped with a perforated metal plate placed 3mlll below the water overflow level. Water was hel~ constant at this level by a constant flow into the container; water was maintained at room temperature (about 21C).
In order to measure rate, the sponge was placed on the surface of the perforated plate such that the measured area was in contact with the plate, and held in this position for exactly five seconds. ~rhe sponge was removed and weighed imme~iately to measure the amount o~
water absorbed. Rate of water absorptioll was then calculated by net weight of water absorbed in 5 seconds rate of absorption = ~
cross sectional area 3. Procedure f r_Meas_ring Wet Wle_ A dry sponge was cut to provide a sample having the dimensions 7.6cm x 10.2cm x 1.3cm and squeezed under water at 21C to remove air. 'l'he sample was tlien squeezed in air using a rubber roller wringer to remove excess water. ~rlle sporlge was therl weiglled and the weight was recorded as M1. 'l'wenty grams of distilled water were 1~66S49 poured onto the surface of a clean glass mirror and without applylng pressu~e, the wrung out sponge sample was passed in five back and forth motions through the water. The sponge was then reweighed and the weight recorded as M2.

M2 _Ml percent wiping capacity = --20--- x 100 Objects and advantages of this invent;on are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to ullduly limit this invention.
~xample 1 - sulfocompound synthesis (step a~
~ one liter flask was fitted with a mechanical stirrer, nitrogen purge, condenser and receiver for condensate. The flask was charged with l.0 moles (600 y) ethyleneoxide polyol (Carbowax 600TM, Union Carbide, Danbury, CT), 0.25 moles (24.0 g) dimethyl sodium 5-sulfoisophthalate (previously dried above 100 degrees C
in a vacuum oven), and 100 g toluene. The flask was heated in a Woods metal bath to 130C to distill toluene and thus dry the reactants. When all of the toluene was removed the reactants were heated to 200~C at which time 0.2 g Zn(OAc)2 is added (0.03 wt%). Esterification accompanied by the evolution of methanol took place. The temperature was raised to 245C for a period of ~ hours, at which time the pressure was reduced to 1 mm for 30 to 60 minutes. Hot resin was tlle poured into dry containers and capped under dry N2 to prevent absorption of water. The O~l equivalence of this diol was typically approximately 465 g/mole Ol~ as determined by the NCO method.

Example 2 - isocyanate endcapping reaction (stèp b) A two-liter flask was fitted with mechanical stirrer, addition funnel, dry nitrogen purge, and oil bath heating. The flask was charyed with 500.0 g of a mixture Ç;6549 of 4,4'-dipllenylmetllane diisocyanate-based polyisocyanates (Isonate 143L , Upjolln, Kalamazoo, MI), and 0.58 g (0.05 wt ~) ethanesulfonic acid (this acid was introduced slowly with rapid stirring). The temperature of this mixture was raised to 60C, at which time the addition of 465.0 g of the sulfodiol prepared as in Example 1 was begun; the addition lasted approximately one hour, at a rate allowing a maximum exotherm of 80C. Wllen addition was complete the reaction was held at 70C for 2 hours, at which time the resin was poured into predried containers under dry N2. An isocyanate-terminated sulfopolyurethane having a typical NCO equivalence of 3~5 g/mole NCO was found to be presellt.
xample 3 - sponge forming reaction 70.0 g of the isocyanate-terminated sulfopolyurethane prepared as in Example 2 was weighed into a 500 ml plastic beaker. In a separate 50 ml beake~ 30 g of water was mixed with 0.35 9 nonionic alkylphenyl polyether alcohol surfactant (Pluronic L-64 ) 0.53 g N-ethylmorpholine, and a water soluble dye ~if desired).
The two were mixed together witll a high speed mechanical stirrer for 20 to 30 seconds at about ~00 rpm, and then immediately poured into an aluminum pan before significant expansion of the resin occurred. CO2 was released in a chemical reaction and caused a porous, open cellular mass to form. The resulting sponge was trimmed to remove the outer skin and it was then oven cured at 50C for 2 hours.
Performance of the resulting sponge designated 3A will be described in Example 4.
This example was repeated except that the mixing of the components witll the higll speed stirrer was for 30 to - 40 seconds to provide a sponge designated 3B.
This example was repeated except that the mixing of the components with the high speed stirrer was for 10 to 20 seconds to provide a sponge designated 3C.

6~5~9 Example 4 Sponges of three different chemical compositions, some having similar densities, were evaluated for water absorption properties. 'l'lle data is shown in ~ABL,E I helow.

51,1r Prt)L~rlles Of Spolllres , . _ . _ . . _ Wet Uells1ty l~d~e(') _X Swell _~1ir)e Hyl)ol-4oo~lM(a) U.()400 .()()2 40-60 45-50~
('ellu~ose()) ().()45() .()]7 3()-6() 9~)-95X
Spon~e 3A ~f ~xaml)l~ 3 U.04()0 .()17 15-25 90--95%
Sponge ~U of Examl)le 3 ().()351) .()l~ 15--25 Sl)onge 3C of Exaa~ e 3 ().()~35 .0]4 15-25 __ ._, _ (a) nol~-ionic spollges l)ase~ ollr)olyetllylelleoxi(le prel)olylner ,Ivaila~le frol~ W.R. (.race.
(l~) Scotch U~-ile~ Ki~cllell ~CL-~ o~lgelM (3M~ St. Pau1, MN) (c) rate of water al)soll)tioll i" ~/col2 I)er ~ ~econds ~ he data of T~BLE I shows that the rate of water absorption and wet wipe of non--ionic sponges are low (0.002 g/cm2 sec and 45 to 90% respectively) relative to cellulose sponges and the sponges of Examp1e 3 ~0.017 g/cm2 sec and 90-95% respectively) and that tlle percentage swell of the sponges of Example 3 (15--25%) is dramatically lower than that of the noll-ionic sponges (40-60%) and cellulose sponges (30-60%).

Example 5 A one liter flask equipped as described in Example 1 was charged with 1.67 moles (250.0 q) triethylene glycol (Aldricll), 1.11 moles (162.2 g) dimetllyladipate (Aldrich), and 100 g toluene. Tlle flask was heated in the Woods metal bath to 140C to distill toluene and thus dry the reactants. There was then added 0.10 g zinc acetate.

-19- ~6549 l~eating was continued to a temperature of 200C. Evolution of metllarl~l took place indicating esterification of the triethylene glycol with adipic acid. There was then added 0.2~ moles (~2.2 g) dimetl~yl sodium 5-sulfoisophthalate (previously dried in a vacuum oven at 100C) and 0.05 9 zinc acetate. 'l'he temperature of the flask contents was then elevated to 250C and held for a period of 5 hours.
The pressure in the flask was then reduced to 1 mm for one hour to remove volatiles. Sulfopolyesterdiols obtained by this process typically had an hydroxyl e~uivalent weight of about 700 as deteLmined by isocyanate titration.
Tlle sulfopolyesterdiol, as obtained above ~350 9) was isocyanate endcapped by reaction with z50 g of Isonate 143 L in accordance with the procedure of Example 2. An isocyanate-terminated sulfopolyesterpoly-urethane was obtained having an isocyanate eyuivalent weight of 5~0 was obtained.
A sponge prepared in accordance with the procedure of Example 3 using the above isocyanate~
terminated sulfopolyesterpolyol had cllaracteristics similar to those of the sponge of Example 3.

Examples 6-15 Sponges were prepared by the reaction according to the procedure described in Example 3 using tlle materials shown in Column A, as indicated in TABLE II. The isocyanate-terminated sulfocompoulld in Column A was prepared according to the procedure described in Example 2 using the moles of Isonate 143L to one mole of sulfocompound sllown in Column B. The sulfocompounds in Column C were prepared according to the procedure described in Example 1 by reaction of one mole of dimethyl sodium isophthalate witll the moles of polymeric diol shown in Column C.
'rlle sulfocompound-containing sponges prepared as described in Examples 6-15 are hydrophilic and exhibit various densities, lates of water absorption, percentage swell and wet wipe characteristics.

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-21-- ~ ~66549 Exam~e 16-22 Sponges, as indicated in TABLE III, were prepared in accordance with step (d) by mixiny 43 9 of the isocyanate-terminate~ sulfocompound of Example 6 using a high spee~ mechanical stirrer for 20 to 30 seconds at about 800 rpm with tlle materials sll~wn, pouring the mixture imme~iately into an aluminum pan, and placing the foaming mixture into an oven at 100C where it is allowed to cure for 30 to 60 seconds and then removed from the oven.

Sllrfac- Bl,0-wING ~GENTS
l'rS(I) Culat;ve(ll) lant(S) Uater Freon 113 _ _ ~x. No. g_ l'olyol Wt(_) _ (g L _ g g 16 43 PCP--()2()~ ) 0.25 _ B
17 43 trimetllanolpropalle (3) 0.25 5.0 8 18 43 castor oil (I1) _ _ tO( ) 19 43 triethy1elleglycol (/) 0.20 - 10 43 s~llfl)col~ ((l) (2~) ~.25 ~ lo(t) 21 43 butal~edlo]. (3.~)) 0.25 5.0 22 53(r~ blltallediol (4.5) - - 10 (n) isocy~rlate-terlninated sulfocompollll(l of Examp:Le 6 (p) I)olycaprolaclonetriol (available from Unioll Carbide) ((1) the sulfoglycol of Exanll)le 7 (r) isocyanate--terllliuated sulfocollll)oull(l of Exanll)le 9 (s) surfactallt was Plurollic l.--64 (t) blowing agent was ~entalle irl place of Freoll 113 (u) tlle catalyst used ill eacll colnllosition was ~.1 g dibutyltin dilaurate It is to be observed that hydrophilic sponges prepared using a polyol curative in place of water can be made to have characteristics similar to those prepared using water as the curative for the isocyanate-terminated sulfocompound.

--22- ~Z~6~49 Examples 23-27 _ _ The procedure of ~xample 16-22 were repeated using as curative polyamines dissolved in water in place of the polyols. 'l'he materials used are shown in TA~LE IV.

'1'~111.1~ I Y
~ S(~ ative ____ S~lr~ctallt(S) (~atalyst(g) Ex. No. _ g _- rolyalllille Wt(g) __ g _ g 23 43 Jeffamine D-2()U()2.0 - -24 43 Jeffamil-le D-200U5.0 0.25 0.25 43 Jeffalllille 1)---23() 1.() 26 43 JefLa~ e ~ 23~ ) 0.25 0.25 27 ~,3 Je~famille D-6()()5.~ 0.25 0.25 _ _ _ _ _ (n) isocyanate-terl~ ate~ sul~ocollloull~ of Exalnl)le No. 6.
(s) Pluronic L--64 (g) N-ethylnlorl)llolille.
(v) dissolved in l5g water The hydropllilic sponges prepared using polyamines in place of water had cllaracteristics similar to those prepared using polyols as curative. Similar sponges can be made using mixtures of polyols and polyamines as curatives.

Example 28 A two liter flask equipped as described in Example 1 was charged witll 3.0 moles (450g) triethylene glycol, 1.0 mole ~1949) dimethyl isophthalate, 1.0 mole (1449) dimethyl maleate, and 150g toluene. Irhe flask was heated in the Woods metal batll to 140C to distill toluene and thus dry the reactants. 0.29 zinc acetate was then added and heating was continued to a temperature of 200C.
Following the completion of methanol evolution 0.5 moles (1489) dimethyl sodium 5-sulfoisophthalate (previoulsy 35 dried in a vacuum overl at 100C) an(l 0.059 zinc acetate were added to the flask. ~he temperature of the flask contents was then elevated to 250C and held for a period ~ ~s ~

--23-~ i5~

of 5 hours. The pressure in the flask was then reduced to 1 mm for 1 ho~r to remove volatiles. Sulfodiols obtained by this process typically have a hydroxyl equivalent weight of about 660 as determined by isocyanate titration.
~ e sulfopolyesterdiol as obtaine(~ above (780g) was mixed with ~ mole (6009) oi: Carhowax 600 and endcapped with 1502g of Isonate 143L in acc:orclance with the procedure of Example 2. An isocyanate-terminated sulfopolyesterpolyurethane was thus obtained having an lO isocyanate equivalent weiyht of 4ao-500.
A sponge prepared in ac~ordance ~ritl~ the procedure of Examule 3 using the above isocyanate-terminated sulfopolyesterpolyol had characteristics similar to those of the sponge in Example 3.
Example 2_ The sulfodiol (4199) prepared as in Example 1 was mixed with 4.59 trimethylol propane, and then endcapped with 500~ of Isorlate 1'13L ac:cordirlg to the procedure of 20 Example 2. '1'he resulting sulfopolyurethane was foamed according to the procedure of Example 3 giving a hydrophilic, resilient, open celled foam.

ExamE~le 30 - isocyanate endcapping reaction (step b) A two-liter flask was fitted with mechanical stirrer, ad~lition funnel, dry nitrogen purge, and oil bath heating. qhe flask was charged with 500.0 g of a mixture of 4,4'-dipherlylmetllane diisocyanate-~ased polyisocyanates (Isonate 143LrM, Upjolln, Kalarnazoo, Ml), and 0.58 9 (0.05 30 wt %) ethanesulfonic acid (this acid was introduced slowly with rapid stirring). rlhe temperature of this mixture was raised to 60C, at which time the addition of 465.0 9 of the sulfodiol prepared as in Example l and 2.3 g water was begun; the addition lasted approximately one hour, at a 35 rate allowing a rnaximum exotherm of 80C. When addition was complete the reaction was held at 70C for 2 hours, at which time the resin was poured into predried containers i6549 under dry N2. ~n isocyarlate-terminated sulfopolyuretharle/urea having a typical NCO equivalence of 430 g/mole NCO was fount3 to be present.
A sponge prepared in accordance with the procedure of Example 3 usin~ the above isocanate~terminated sulfopolyuretllarle/urea llad characteristics similar to those of the sponge in Example 3.
Various modifications and alternations of this invention will become apparent to tllose skilled in the art without depar-ting from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to ttle illustrative embodiments set forth herein.

Claims (17)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A water-absorbing sponge comprising at least one of a sulfo- group containing polyurea and polyurethane, the polymer containing at least one sulfonate equivalent per 20,000 molecular weight units.

2. The sponge according to Claim 1 comprising a plurality of units having the formula wherein R is an organic group having a valence of 2, 3, or 4, selected from linear and branched aliphatic groups havlng 2 to 12 carbon atoms, 5- and 6-membered aliphatic and aromatic carbocyclic groups having 5 to 50 carbon atoms, each R1 is independently a linear or branched aliphatic group having a valence of (b + 1) consisting of a chain of up to 110 carbon atoms in units selected from linear groups CnH2n and CnH2n-2 in which n is 2 to 12, 5- or 6-membered carbocyclic groups, and aromatic groups of 5 to 20 carbon atoms, which are separated by individual oxygen atoms, groups, the aliphatic group having a molecular weight of up to 2000, wherein b is an integer of 1, 2, or 3; and R2 has a valence of d+2 and is an arenepolyyl group (polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atoms, wherein d is a number 1, 2, or 3, X is independently -O- or -NH-, and M is a cation.

3. The sponge according to Claim 2 further comprising a plurality of units selected from the group consisting of wherein R3 is a linear or branched aliphatic group having 2 to 50 carbon atoms or an aromatic group of 5 to 50 carbon atoms having a valence of c in which c is a number having a value of 2 to 5, the group optionally containing 1 to 20 nonperoxidic oxygen atoms, groups or R3 is a 5- or 6-membered cycloaliphatic group or aromatic group having 5 to 20 carbon atoms.

4. A sponge comprising the reaction product of a) an isocyanate-terminated sulfopolyurethane/urea comprising in its backbone linear or branched organic groups selected from the group consisting of 1) aliphatic, cycloaliphatic or aromatic ether groups and 2) aliphatic, cycloaliphatic, or aromatic ester groups, and a central arenepolyyl or alkanepolyyl group containing 1 to 3 pendant sulfonate groups, that are end-capped with isocyanate groups, and b) coreactants which include at least one of 1) water, 2) a polyol plus a blowing agent, and 3) a polyamine plus a blowing agent.

5. The sponge according to Claim 4 wherein said isocyanate-terminated sulfopolyurethane/urea comprises a compound having the formula and, optionally, at least one of compounds having the formulae OCNR(NCO)a and wherein R is an organic group having a valence of (a +1) selected from linear and branched groups having 2 to 12 carbon atoms, 5- and 6-membered carbocyclic groups having 5 to 50 carbon atoms; a is a number having a value of 1, 2 or 3;
R1 is independently selected from a linear or branched organic group having a valence of (b +
1) comprising a saturated or unsaturated chain of up to 110 carbon atoms selected from linear groups CnH2n and CnH2n-2 in which n is 2 to 12, aromatic groups of 5 to 20 carbon atoms, and 5-or 6- membered carbocyclic groups, which optionally are separated by individual oxygen atoms, groups, the organic group having a molecular weight of up to 2000, wherein b is an integer of 1, 2, or 3;

R2 has a valence of d+2 and is an arenepolyyl group (polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atoms, and d is a number having a value 1, 2, or 3;
X is independently -0- or -NH-; and M is a cation.

6. A sponge comprising the reaction product of a) an isocyanate-terminated sulfopolyurethane/urea having at least one of the formulae b) a polyisocyanate having the formula OCNR(NCO)a , c) an isocyanate-terminated polyurethane/urea having the formula wherein R is an organic group having a valence of (a + 1) selected from linear and branched groups having 2 to 12 carbon atoms, 5- and 6-membered carbocyclic groups having 5 to 50 carbon atoms;
a is a number having a value of 1, 2 or 3;
R1 is independently selected from a linear or branched organic group having a valence of (b + 1) comprising a saturated or unsaturated chain of up to 110 carbon atoms selected from linear groups CnH2n and CnH2n-2 in units of 2 to 12 in which n is 2 to 12, aromatic groups of 5 to 20 carbon atoms, and 5-or 6- membered carbocyclic groups, which optionally can be separated by individual oxygen atoms, groups, the organic group having a molecular weight of up to 2000, wherein b is an integer of 1, 2, or 3;
R2 has a valence of d+2 and is an arenepolyyl group (polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atoms, and d is a number having a value 1, 2, or 3, X is independently -0- or -NH-, M is a cation, and d) a compound selected from the group consisting of (1) water, and (2) a polyol or a polyamine plus a blowing agent.

7. The sponge according to Claim 1 having an absorptive capacity of 10 to 50 grams of water per gram of dry sponge.

8. The sponge according to Claim 1 having a rate of water absorption of 0.001 to 0.04 g/cm2/5 sec.

9. The sponge according to Claim 1 having a density in the range of 0.01 to 0.4 g/cm3.

10. The sponge according to Claim 1 having a percentage volumetric swell in water of 25 to 50%.

11. The sponge according to Claim 1 having a percentage volumetric swell in water of less than 30%.

12. The sponge according to Claim 2 wherein M is H, an alkali or alkaline earth metal cation, or a primary, secondary, tertiary, or quaternary ammonium cation.

13. The sponge according to Claim 1 further comprising adjuvants selected from the class consisting of fibers, fillers, deodorants, medicinals, insecticides, fungicides, antimicrobials, humectants, pigments, or dyes.

14. The sponge according to Claim 1 wherein said polymer contains one sulfonate equivalent per 3,000 to 10,000 molecular weight units.

15. A method of preparing a sponge comprising the steps of a) providing an isocyanate-terminated sulfopolyurethane/urea comprising a compound having the formula and, optionally, at least one of compounds having the formulae OCNR(NCO)a and wherein R is an organic group having a valence of 2, 3, o 4, and is selected from linear and branched groups having 2 to 12 carbon atoms, 5- and 6-membered carbocyclic groups having 5 to 50 carbon atoms, R1 is independently selected from a linear or branched organic group having a valence of (b + 1) comprising a saturated or unsaturated chain of up to 110 carbon atoms selected from linear groups CnH2n and CnH2n-2 in units of 2 to 12 -CH2- groups in which n is 2 to 12, aromatic groups, and 5- or 6-membered carbocyclic groups, which are separated by individual oxygen atoms, groups, the organic group having a molecular weight of up to 2000, wherein b is an integer of 1, 2, or 3; and R2 has a valence of d+2 is an arenepolyl group (polyvalent arene group) having 6 to 20 carbon atoms or an alkanepolyyl (polyvalent alkane) group having 2 to 20 carbon atoms, wherein d is a number 1, 2, or 3;
X is independenetly -O- or -NH-, and M is a cation;
b) reacting said sulfopolyurethane/urea with at least one of (a) water, and (b) at least one of a polyol or polyamine plus a blowing agent, and c) isolating the resulting sponge.

16. The method according to Claim 15 wherein said polyol or polyamine has the formulas R3(OH)c and R3(NH2)c wherein R3 is a linear or branched aliphatic group having 2 to 50 carbon atoms and a valence of c in which c is a number having a value of 2 to 5, the group optionally containing 1 to 20 of at least one of nonperoxidic oxygen atom, groups, or R3 is a 5- or 6-membered cycloaliphatic group or aromatic group having 5 to 20 carbon atoms.

17. A method of absorbing a liquid comprising the steps of:
a) providing a sponge comprising at least one of a sulfogroup-containing polyurea and polyurethane, the polymer containing at least one sulfonate equivalent per 20,000 molecular weight units, b) contacting said sponge to said liquid for a time sufficient for said sponge to absorb all or a portion of said liquid.